A roller press, also referred to as a material-bed grinding roll, has two rollers between which a bed of material is comminuted by means of a high pressure. The high pressure thereby causes high wear of the rollers. Various solutions have been proposed to reduce this wear.
In principle, surface profiling of rollers is acknowledged to be wear-reducing, whereby profiling may be applied in a number of ways. For example, EP 0443195 A1 proposes the application of burls on the roller surface by welding.
DE 10 2010 024 221 A1 proposes a bandage for a roller press consisting of a high-chromium ferrous alloy. The bandage is formed with a profiled external surface to improve wear protection. Besides the high costs of the alloy, applying the bandage is a complicated process step, resulting in high total costs.
DE 41 32 474 A1 proposes that wear-resistant pieces of material, which are harder than the surrounding rolling material, be embedded in the roller surface. The material pieces are preferably plate- or pin-shaped, connected to the roller by means of bonding and made of carbide. The cost of the carbide material pieces is high, which is a disadvantage, and moreover, carbide is too wear-resistant and brittle for various application purposes.
Document EP 2239058 A2 discloses a wear-resistant roller and its production. The roller includes a plurality of wear-resistant surface elements, preferably bolts, the free bolt ends protruding radially from the surface of the roller. The spaces between the bolts are filled with a matrix material that is softer than the bolts and ground material is refilled on [top of] the matrix material. The bolts are welded on the roller and consist, at least partially, of a high-strength ferrous alloy. A disadvantage is the complex and costly manufacturing process for the device.
DE 10 2011 104 854 A1 proposes to place the hard bodies in a sleeve and insert them into the roller surface. This allows for the hard bodies to be released from the roller surface in an easier way.
The present invention is directed to addressing these and other deficiencies in the art.